1. Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution.
- Author
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Koh HR, Roy R, Sorokina M, Tang GQ, Nandakumar D, Patel SS, and Ha T
- Subjects
- DNA-Directed RNA Polymerases genetics, Humans, Protein Binding, Protein Subunits, RNA genetics, RNA metabolism, Viral Proteins genetics, DNA-Directed RNA Polymerases chemistry, DNA-Directed RNA Polymerases metabolism, Promoter Regions, Genetic, RNA chemistry, Transcription Initiation Site, Transcription, Genetic, Viral Proteins chemistry, Viral Proteins metabolism
- Abstract
We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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